These glass strawberries are the most technically difficult berries I make. They are formed by the lampworking process, which involves melting Italian glass rods in the flame of a torch. The glass is melted over and around a loop in a length of copper wire of appropriate thickness, which then becomes the strawberry stem. Because of the loop, the stem can never be pulled free of the glass berry.
The process of making the glass strawberry begins with preparing the sepals (leaves). I make several dozen glass sepals in a range of sizes ahead of time. I keep them warm on a hot-plate so that later, when they are re-introduced into the torch flame and attached to the strawberry, they will not crack.
I also pre-make fine threads of glass (called stringers) in several shades of green and brown. These will be used later to make the strawberry seeds.
Finally I'm ready to begin building the body of the strawberry onto the wire stem. This can be a difficult process because the glass must be shaped without allowing any portion of it to become too hot. Overheating this type of red glass can make it turn brown. Although the strawberries you see pictured here are mostly a ripe medium red, I can also make them in a less-ripe orange red, or over-ripe purple red. Many of the strawberries you'll see on this website have a shape referred to as "conic", but I can make them more globe-shaped, wedge-shaped or multi-lobed, just like real strawberries varieties. The size can be anywhere from tiny (about 14mm high) to quite large (about 40mm high).
Once the shape is achieved, the entire body of the strawberry must be kept at an even temperature of about 950 to 1000 degrees F for the remainder of the time I work on it. Letting any part of the strawberry get too cool (below about 850 degrees) will cause the glass to crack or even explode. Letting any part of it get too hot (about 1050 degrees) causes that part to melt and lose its shape.
Now the time-consuming job of adding the seeds begins. Each seed is placed one at a time into its own recessed seat in a process that takes up to half a minute per seed. I must pause after placing each seed to rotate the entire strawberry in the flame to even out the heat. The tiniest strawberries have at least 50 seeds, and the largest can have four or five hundred seeds. As you can imagine, on a large strawberry this process can take many hours.
After all the seeds have been placed it is time to finish the strawberry by adding the green sepals (leaves). This is the most dangerous time. Although in real life the sepals of a strawberry often curl upward, these glass sepals must be laid down flat and thoroughly melted to the surface of the strawberry. This makes the thin glass sepals strong enough to withstand the weight of the glass berry without breaking off. If any sepal gets too hot (much over 1050 degrees F) in the process, the edges will soften and the sepal will melt back into a shapeless green blob. I must carefully apply each sepal, and then reheat the whole strawberry to even temperature before going on to the next sepal. If I forget the reheating step in my zeal to get the sepals perfect, some other part of the strawberry gets too cold and the sculpture cracks.
Needless to say, I have exploded many nearly-complete strawberries in an effort to balance all these factors. This is especially frustrating after having spent hours to place all the seeds. But when I am successful in adding all the sepals without allowing the strawberry body to crack or allowing any of the sepals to melt, I'm nearly done. The final step before putting the strawberry in the kiln for controlled cooling is to melt the free end of the copper stem into a rough ball.